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Feb. 8, 2011 (New Orleans) -- Exposure to amounts of pollution typically found in urban environments may more than double skin damage from the sun, preliminary research suggests.

Extreme weather and smoking may also increase the skin damage associated with ultraviolent (UV) radiation, the study suggests.

Michelle Garay, MS, of Johnson &amp; Johnson Consumer Companies in Skillman, N.J., and colleagues presented the findings at the annual meeting of the American Academy of Dermatology (AAD).

It's well known that repeated exposure to ultraviolet radiation from the sun or tanning beds can cause wrinkles and other skin damage and even lead to skin cancer. But researchers wanted to see if exposure to pollution and other environmental factors, such as extreme temperatures, would further aggravate damage from UV rays.

Testing for Sun Damage

The researchers placed skin cells in a variety of special chambers mimicking different environmental conditions, including:

UV radiation alone.

UV radiation plus cigarette smoke.

UV radiation plus heat reaching 104 degrees Fahrenheit.

UV radiation plus temperatures dropping below freezing.

UV radiation plus high winds.

UV radiation plus ozone.

Then the researchers measured key chemicals associated with premature aging of the skin due to sun damage.

Levels of all the chemicals were higher in skin cells placed in chambers that included a second environmental stressor than in the chamber with UV radiation alone.

Past AAD president Darrell S. Rigel, MD, clinical professor of dermatology at New York University Medical Center in New York City, says that while preliminary, the work generates new hypotheses that deserve testing.

"I don't think anyone has ever looked at this before," he tells WebMD.

The AAD already advises people to use extra sun protection near water, snow, and sand as they reflect the damaging rays of the sun that can increase your chance of sunburn, Rigel says. "It could be that people who live in polluted areas also need extra sun protection, though that remains to be tested."

These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.